Does anyone know of a resource for or formula to figure out BTU for equipment. Or even a good rule of thumb? Looking for a way to add up the components in a system and give HVAC guys a BTU number and a desired temperature for our equipment rooms. Some of the high end manufacturers have this info for their amps, but I find it woefully lacking in a lot of spec sheets. I'm not even sure if this is the way to approach this. Any suggestions would be greatly appreciated!

TIA
James